The present invention relates to a drive system for an agricultural large baler with a device for picking harvested product from a field, a device for further transporting the harvested product to a pressing chamber, a pressing chamber, a binding device, as well as a discharge device for discharging the finally bound bales.
Such a large baler is disclosed for example in the patent document DE 92 06 232. The large baler shown in this reference includes an arrangement for automatic interruption and subsequent pre-switching of the drive train, located between the flywheel and the main transmission, for protecting the components of the large baler from an overloading. If the drive train in such a large baler is interrupted or the power pickup of the tractor is suspended to stop the working elements of the large baler, there is the disadvantage that in addition to the mechanical drives which transmit the drive force through for example toothed gears, shafts and chains, also the hydraulic drive must be stopped for example for the upward and downward movement of the pickup device, for the pressure chamber additional adjustment, for opening of a rear flap in a round baler, the bale pressing out element, the bale constricting element, or the binding device. The reason is that the hydraulic pumps are usually mounted on the main transmission of the baler or after it, and after the switching-off do not have any drive power.
U.S. Pat. No. 2,676,532 discloses a construction in which a hydraulic pump is arranged near a tractor and is driven through a wedge rim. Such a design of the drive has however the disadvantage that it is dirt-sensitive and maintenance-intensive. More seldom the hydraulic supply is performed through the tractor, in which case dirtying problems arise because of the plug coupling. Partially, in this case hydraulic pressure accumulators are required on the baler or devices for an emergency hydraulic operation, which are expensive and need maintenance.
A further disadvantage of the prior art is that the input shaft of the main transmission is regularly higher than the drive end of the power take-off, while the hinge shaft which transmits the drive force from the power take-off to the input shaft of the main transmission must be arranged during the operation of the baler inclined to bending angles on the hinge locations. Due to this arrangement, the bending potential of the hinge shaft is used partially, a higher wear occurs on its hinges, and the force flux is not optimal. Also, different machine rotary speeds and eventually a reverse in the known drive systems are not easy to realize. The patent document DE 19 36 188 discloses an intermediate lock transmission, which can be plugged between the drive shafts in two ways to provide rotary speeds of 540 or 1000 revolutions per minute for the drive of an agricultural machine. The disadvantages of the proposed plug transmission are that, no connecting possibility for a hydraulic pump is provided and the hinge shafts can not be optimally oriented.